Expansion strip for concrete roadways



Aug. 27, 1929., D. GREGG I ExPKNsIon' STRIP FOR CONCRETE ROADWAQSOriginal Filed April 21, 1 92? F/Gf]. 56.3.

INVENTOR. 0055A 710. 5/7566,

ATTORNEY..

Patented Aug. 27, 1929.

UNITED STATES 1,726,263 PATENT OFFICE.

ROBERT D. GREGG, OF KANKAKEE, ILLINOIS, ASSIGNOR OF ONE-HALF TO FRANK L.SHIDLEIL OF KANKAKEE, ILLINOIS.

EXPANSION STRIP FOR CONCRETE ROADWAYS.

Application filed April 21, 1927, Serial No. 185,504. Renewed February9, 1929.

This invention relates to that type of parting strips or plates used inthe formation of sectional concrete roadways, pavements, etc., in whichthe strip or plates remain in 5 the completed roadway or the like toconstitute an expansion joint for the same. And the present improvementhas for its object To provide a structural of a flat parting strip orplate, preferably composed of a fiber and asphalt combination, generallyknown as'tar board, adapted to provide an effective bonding of the stripor plate with the mass of roadway concrete, and which at the same timeadmits of a ready removal of the usual bracing board by which theparting strip or plate is held in position, without any disturbance inthe relation of the strip 01 plate to the mass of unset roadway concretethat is held in form bythe strip or plate and without damage to theupper corner or edge of said unset concrete mass, all as willhereinafter more fully appear.

In the accompanying drawing: I

Fig. 1, is a detall vertical section, illustrating the ordinary mannerand means for positioning the parting strip in the. formation of asectional concrete roadway or the like, the strip embodying the featuresof this invention.

Fig. 2 is a detail elevation of the face of the parting strip remotefrom the concrete receiving cavity of which the strip forms one wal Fig.3, is a similar' view of the face of 0 strip within said receivingcavity..

Fig. 4, is a detail longitudinal section of the strip, on line 44: Fig.2.

Fig. 5, is a detail elevation of a modified form of the face of thestrip shown in Fig. 2.

Like reference numerals indicate like parts in the different views.

The parting or expansion strips now in general use in the making ofconcrete roadways are known to the trade as tar boards 0 which areformed of a body of fibrous material saturated-with tar, asphalt, orlike bonding and preservation material of an elastic nature. The presentimprovement, in connection with such type of parting and expansionstrips, involves a special formation of the respective faces of a stripof such nature affording a firm anchorage or connection of the side ofthe strip-which forms one wall or face of the concrete receiving cavity,with the mass of roadway eoncrete in said cavity, and by means of whichthe bracing board by which the parting and expansion strip is held inproper place, can be readilyremoved after the filling and partialsetting of the concrete materlal in said cavity, without displacement ofthe strip or injury .to the adjacent upper edge of such concrete mass.The attainment of such results are effected in the present improvementby a detail formation of a tar board strip in manner as follows One sideor face of the tar board strip 1, is formed with a series of depressions2, preferably arranged in longitudinal rows, with such side or faceadapted to form a wall of the receiving cavity of a mass of roadwayconcrete, and into which depressions 2the plastic concrete roadway inassis adapted to enter andprovide a connection of parts adapted to preventrelative independent vertical'movement between the surfaces in contact.In connection with such formation of the strip 1, a material part ofthis invention consists in forming the opposite "face or side of the tarboard strip l 'with a series of transverse depressions 3, in angularrelation to the aforesaid depressions 2, preferably in right-anglerelation, the purpose being to reduce frictional or adhesive contactbetween said face of the parting strip and the bracing board or plank 4by which the parting strip is held in proper position to constitute onewall of the receivingcavity in which the roadway forming mass ofconcrete 5 is placed and molded. The bracing board 4 is held in'place bythe usual anchor stakes 6, or other usual means, as illustrated in Fig.l.

With the above described formation and arrangement of parts, and afterthe concrete mass 5 has partly set, the bracing board 4, can be readilyremoved without liability to disturbance of the parting strip in itsproper relation to the mass of concrete and without. I

danger of injury to the upper edge or corner of such concrete mass. vHaving thus fully described my invention,

what I claim and desire to secure by Letters Patent, is

1. A tar board expansion stripvfor concrete roadways formed with aseries of depressions in the face which forms a wall of the receivingcavity for a mass of roadway -concrete andwith a seriesof transversedepressions at right angle. relation to the afore saiddepressionsand inits other face, adapttudinally extending depressions in the face- -whichforms a wall of the receiving cavity for a mass of roadway concrete, andwith a serieswof transverse depressions at rightangle relation to theaforesaid depresslons and-in its other face, adapted to reduce theextent of adhesive contact with a bracing Y board-used to hold theparting strip in position in the formation of the roadway.

3. A tar board expansion strip for concrete roadways having a series ofdepressions in the face whichforms a wall of the receiving cavity for amass of roadway concrete, said depressions extending approxi: matelylengthwise of the strip, and in its opposite face with a series ofdepressions extending approximately transverse of the strip, the firstmentioned formation providing effective retardance againstindependentupward movement of the expansion strip in relation to theconcrete roadway mass, while the last mentioned formation provides foran easy upward removal. of the ordinary bracing board, withoutdisturbance of the proper relation of the expansion strip and the partlyhardened roadway mass.

Signed at Chicago, Illinois, this 16th da of April, 1927. ROBERT D.GREGG.

